This is a really good question and one that my wife and i thought about for several years before trading in for a new trailer. It boils down to what is the right size trailer/features that we needed as we got into retirement and likely longer trips. Coming from a 16 foot with no bathroom and limited storage we realized that long trips would be more comfortable with the following options.
1. Beds that we did not have to put up and take down
2. shower
3. Toilet / composting so we did not have to break camp to drain black water.
4. good working kitchen
5.
fridge, 4 cubic feet has worked well
6.
Solar and a good size
battery bank. 300+ amp hours (3 batteries)
7. storage that can be accesses easily for clothes etc.
8. under 25 feet for access to most sites.
9. high lift suspension for clearance
10. four season without the dreaded winter condensation
11. Robust construction
With that as our wish list we started looking and it became obvious that there are few trailers that have even 80% of our dream trailer. Many visits to Airstream lots and looking on line at Bigfoots, Casitas and Escapes. The
fiberglass trailer appeared to have the edge, and the width of the Airstream gave it great interior appeal however it was a negative in terms of off road and tight forest road drives. I guess the question we got to answer by doing all the research was how were we going to use the trailer. They were all good in ways but we had to prioritize the features that suited us. The size factor was obvious from the beginning. My saying is that your trailer/rv size is inversely proportional to the amount of use it will see. If not full timing then small size was preferred with the right features. We started to look at what was the minimal size that would incorporate most of our desires. Since we like to boondock and avoid large campgrounds and sites full of large rigs where people mostly stay inside we wanted a trailer that we could hole up in during a storm but one where we spent alot of time outside as well.
So the short answer is that getting older does not always lead to a larger rig and in some people it leads to small ones. I
sold my 2009 Basecamp to a retired gentleman that had stared full timing in a 40 foot Class A and after two years went to a 25 foot trailer and after five years full timing was buying a condo and wanted to scale down to my little trailer. We ended up going up in size to 23.5 feet and got everything we wanted.